Dasystigma tyleri, Mesibov, 2003

Mesibov, Robert, 2003, A new genus of Tasmanian millipedes (Diplopoda: Polydesmida: Dalodesmidae) with unusual spiracles and a mosaic distribution, Memoirs of Museum Victoria 60 (2), pp. 197-206 : 204-205

Dasystigma tyleri sp. nov.

Figs 3E, 5E, 12, 13, 14 (map)

Material examined. Holotype. Male, Australia, Tasmania. Donaghys Hill , approx. DP120270 (42°12´S 145°56´), 480 m, 29 Apr 1987, N. Platnick, R. Raven and T. Churchill, QVM 23 :41729.

Paratypes. 1 male, Little Florentine R., DN525683 (42°44´10´´S 146°25´10´´E) 440 m, 2 Dec 1986, R. Bashford, QVM 23 :40796; 1 male, Trackham Creek , CQ822092 (41°27´36´´S 145°35´22´´E), 630 m, 28 Oct 1991, R. Mesibov, QVM 23 :15180; 1 female, Wedge Inlet, DN379569 (42°50´16´´S 146°14´24´´E), 350 m, pitfall emptied 16 Nov 2001, D. Driscoll, sample EY4-75, QVM 23 :24954.

Other material. 16 males, 4 females and 9 juveniles from 23 unique localities including Acheron Cave environs, Algonkian Mountain, Dismal Creek, Dohertys Range, Franklin R., Goderich Rd, Gordon R., Hardwood R., Hermit Hill, Laughing Jack Lagoon, Little Florentine R., Loddon R., Mt Rufus, Olga R., The Clump, Trackham Creek, Wakefield Creek, Wedge Inlet and White Spur.

Diagnosis. Differs from other Dasystigma in having a heavily toothed femoral process with teeth on anterior margin and small spiracles with no “hairiness” visible at low magnification, with posterior spiracle located just anterior to posterior leg on diplosegments.

Description. As for genus except in following details. Posterior spiracle on diplosegments ( Fig. 5E) positioned just anterior to posterior leg and very clearly separated from anterior spiracle; hair-like structures only just emergent from spiracles, not apparent at low magnification; spiracles of size typical for dalodesmids. Paranotal margin slightly convex; posterior corner projected caudad and slightly mesad ( Fig. 3E). Gonopod telopodite ( Figs 12, 13) with prefemoral process narrowing sharply distad, truncated apex curving caudad and shallowly notched; on posterior surface a small tooth near apex; uncus apparently bifid, with second, caudally projected tip arising from its lateral edge. Femoral process arising in small depression on lateral surface of telopodite, projecting distad and slightly mesad. Femoral process massive, divided into broadly lanceolate anterior portion and robust posterior spike; entire margin of lanceolate portion with numerous heavy teeth, spike extending just past most distal teeth and nearly reaching as far distad as apex of prefemoral process.

Distribution and macrohabitat. An uncommon species in rainforest and wet eucalypt forest over c. 11 000 km 2 in western Tasmania, from Lake Pedder north to Balfour in a band 70–90 km wide extending inland from the west coast ( Fig. 14); c. 50–1000 m elevation.

Etymology. In honour of the Australian limnologist Peter A. Tyler, whose investigations in Tasmania led to the recognition of the biogeographic divide known as Tyler’s Line.

Remarks. There is little morphological variation over the D. tyleri range, but mature specimens tend to be somewhat larger and more heavily pigmented in northwest Tasmania than in the Southwest.